01 -
Set the oven to 200°C and line a large baking tray with parchment paper.
02 -
Heat a large skillet over medium-high heat. Add ground beef or sausage and cook for 7–8 minutes, stirring occasionally, until thoroughly browned. Drain excess fat if necessary.
03 -
While the meat cooks, gently remove stems and scoop out the gills from each Portobello mushroom cap.
04 -
Dice the green pepper and red onion. Grate mozzarella cheese if not pre-shredded.
05 -
Arrange mushroom caps, gill-side up, on the prepared baking tray. Season with salt, black pepper, Italian seasoning, and chili flakes as desired.
06 -
Spoon pizza sauce into each mushroom, then top with cooked beef, diced vegetables, and an even layer of mozzarella cheese.
07 -
Transfer the tray to the preheated oven and bake for 15 minutes, or until cheese is fully melted and toppings are bubbling.
08 -
Serve hot immediately, or allow to cool before freezing in an airtight container for up to 3 months. To reheat, bake from frozen at 200°C for 10 minutes.